The present invention relates to finishing of a foil, and more particularly, to a method for finishing the rounded lengthwise edge of the foil blade.
There are numerous forms of foils to which this invention is applicable, which are provided in various sizes and shapes for use in different machinery, such as engines, compressors, turbines, or the like and which operate in conjunction with different fluid mediums, such as water, steam, air or the like. In the manufacture of such foils, they are cast, forged, or otherwise preformed to a predetermined shape in accordance with NACA specifications. In this preformed state, the surface of the blades is rough and must be further finished to provide a precise, smooth exterior surface. More particularly, the blades are preformed so as to have rounded lengthwise extending edges. It is extremely important that, in the finished form, these lengthwise edges have an extremely smooth contour so as to be substantially free of any flat spots or corners. Still further, it has also been found desirable to provide an arrangement whereby numerous blades may be finished simultaneously and in a substantially automatic manner while maintaining the high precision that is necessary.